Artificial hand



H. F. ARMSTRONG.

ARTIFICIAL HAND. APPLICATION FILED NOV. 27, 1920- RENEWED DEC- 6, I921.1,409,513.v

Patented Mar. 14,1922.

IIVI/ENTOR mstfofiy.

WITNESSES ATTORNEYS UNITED STATES PATENT org-non.

.RoBEnrFRANoIs Anilrs'rnono, OFLA c'YGNn, KANSA; AssreNoa T0 FREDERICK.w.

. POLLMAN, an, or LA cYGNnxANsAsn r ARTIFICIAL Haivn.

Specification of Letters Patent. Patented Dial. 1922.-

Application filed November 27; 1920, Serial No. 426,798. RenewedDecember 6; 1921.: Serial No. 520,403.

To all whom it may concern: 1

Be it known that I, Ronnn'r FRANCIS ARM' STRONG, a citizen of the UnitedStates, and

a resident of La Cygne, in the countyof' Linn and State of Kansas, haveinvented certain new and useful Improvements in Artificial Hands, ofwhich the following is aspecification.

My invention relates in general to artificial hands, and moreparticularly to an improved artificial hand of the type forming thesubject-matter of my Patent No. 1,334,689, and my co-pendingapplication, Serial No. 373,518. 4

The object of the invention is to provide an improved artificialhand ofthis character which is capable of readily and easily performing all ofthe important functionsof the human hand' and which is of extremelysimple and durable construction reliable in operation and easy andinexpensive to manufacture. V v Other olnects andadvantages of theinvention reside 1n certain novel features of construction, combinationand arrangement in section for the sake of illustration; and

Figure 4: is a detail view in section of the tip of the thumb member.

Referring-to the drawings it will be seen that both embodiments of theinvention contemplate a hand body or hand proper designated at 5, middlefinger 6 and thumb fingers 7' are associated with the hand body 5. Indexfinger members 8 are provided and are arranged with thehand body 5 so asto be capable of partaking of a swinging 'motion toward and away fromthe adjacent middle finger on an axis extending substan tiallyperpendicularly through the body of the hand from the palm to the backthereof. A thumb member 9 is also pivotally connected to the hand bodyand the top or outer extremity of the thumbmember is adapted to engagethe index finger member as shown inthe drawings. An operator 10 for thethumb member is provided, as shown in Figure '1. 1

The thumb member isadapted to coaot with the index finger Inemberin'thehandling or manipulation of small articles and in order to provide forthe high degree of grasping action as betweenth'e thumb member and theindex finger member the'tip or outer extremity of the thumb member .is

provided with a kerf 11 (see Figure 4). A gripping element l2 of feltor" the like, is

arranged and secured inthe kerf '11 and projectsbeyond the periphery ofthe tipof thethumbon both'sides thereof. Whenthe thumb member is engagedwith the'index finger member the gripping element 12 provides correctgrasping action espe'cially;fo1' the proper handling of small objectssuch-as pins, sheets of paper and the like. I

In the form of'my invention shown in Figure" 1, the hand body 5"isprovided with slot 13 extendinginteri-orly of the hand body from onesidethereof and substantially parallel with the plane of the palm of thehand. A swinging bar or lever 14: carries the index finger. The bar 14is provided centrally with a circular enlargement 15 having centrallythereof a pivot opening 16 through which a pivot pin 17 journaled in thebody of the hand extends whereby topivotally connect the swinging bar11' to the hand body in such manner as to constrain the same toswingingmovement on an axis extending substantially parallel to the handbody to the back thereof. The swinging bar or lever 14 is also providedwith an extension 18 which operates in the slot 13, as shown inFigure 1. The extension 18is providedwith an inwardly curved hooked end19 having a notch 20 therein.

A retractile coil spring 21 has one end thereof engaged with the notchedportion of the hooked end'19 offthe extension to the swinging lever, asindicated at 22 and has its opposite end secured to a fixed abutment 23,as shown at 24:. The retractile coil spring 21 serves to bias the indexfinger in that it is so tensioned as to exert a pull upon the extension18 of the swinging lever to throw the swinging lever about its pivot 17in a clockwise direction whereby the index finger is urged at all timesagainst the middle finger.

In the embodim nt o my invention shown 1 0 in Figure 3, the hand body 5is provided with a slot similar to the slot 18 and is further providedwith a bore 26 extending transversely of the hand body and intersectingthe slot 25. A swinging bar or lever 27 carries the index finger and ispivoted to the inthe bore 26 and has one end directly engaging andabutting the extension 29, as shown at 31. The opposite end of the coilspring is received within the socket 33 formed in the adjustableabutment 32 and which has threaded engagement, as indicated at 38 withthe wall of the bore 26. The compression coil spring serves to bias theindex finger that is, it serves to urge the same against the middlefinger The tension of the compression coil spring 30 is variable and thevariationsof this tension may be effected by simple manipulation of theabutment 32. In order torender the abutment 32 easily operable itispreferably provided witha slot 35. a -v Having thus described myinvention, I claim: l r

1. An artificial hand having a hand body 7 provided with a slot and abore intersecting the slot, an index finger adapted to swing about anaxis extending substantially arallel through said hand from the palm tothe 1 back thereof, a swinging bar 01' lever carrying said index fingerand pivoted to said hand, said swinging bar or lever having anextension'operating in said slot, a compression coil spring arranged insaid bore and having one end abutting said extension to bias said indexfinger and an adjustable abutment at the opposite end of said springhaving threaded engagement with said bore.

2. An artificial hand having a hand body provided with a slot and a boreintersecting said slot, a swinging'index finger,-a swinging. bar orleverpivoted to said hand body and carrying said index finger, saidswing: ing bar'or lever having an extension operating in said slot, acompression coil spring arranged in .saidbore and having one endabutting said extension to bias said index finger, and anadjustableabutment for the opposite end of saidooil spring having threadedengagement with said bore.

3. An artificial hand having a hand body comprising a solid stockprovided with a transverse slot therein, a swinging index.

finger, a bar or lever carrying said index finger and pivotallyconnected to the hand body, said bar orlever having an extension andsaid extension and saidbar Or lever operating in said slot, a coilspring having one end engaged with the'extension for biasing the indexfinger, and van abutment'carried by the stock and engaging the oppositeendof the coil sprin ROBERT FRANSIS ARMSTRONG.

